As the performance of computer systems increases, so does the amount of heat generated by various system components. Careful management of airflow is required to effectively cool computer systems down. The difficulty of cooling high power computer systems such as a computer server has grown as a result of demand for vastly more powerful processors combined with a similarly strong demand for smaller system form factors, such as a computer server enclosed in a 1 U housing.
Various structures and techniques may be used to effectively cool down a computer system. Heat is generated by the various system components and is removed to the surrounding air stream. Typical techniques for cooling involve fan-type assemblies mounted on or near heat-dissipating components, e.g., heat sinks. High-power processors create a demand for extremely efficient cooling devices, particularly in systems contained within constraints of dense form factors. Typically, an air duct is used to direct airflow with little air leakage to direct high-pressure air from system fans through processor heat sinks. For example, heat sinks may have a very high fin count in a compact geometry so the pressure drop across the heat sink is significant. As a result, small leaks in the air duct result in diversion of cooling air and poor thermal performance.
Conventional air ducting structures for servers have traditionally required elaborate and expensive plastic parts with fasteners, as shown in FIG. 1, designs which are inflexible to changes in system designs and involve many months of development time prior to deployment. A conventional plastic or metal air duct typically does not make an airtight seal against a printed circuit board at least partly due to obstruction from components mounted on the printed circuit board.